Engineering topics

Kovalenko, Y. A.

Publications and source records attributed to Kovalenko, Y. A..

11 records

NASA NTRS1983

Life in motion, in motion!

A 120 day limited mobility experiment with young male rats and its results, including retarded growth and degenerative changes in the cardiac muscle, are described. A 120 day strict bedrest experiment with 10 human volunteers and its results are described and discussed. Early subjective complaints, subsequent adaptation and eventual progressive changes in excitability and reactivity, reduction in functional capability of the cerebral cortex, and disturbances in water-salt, protein and fat metabolism, including development of precursors of atherosclerosis, as well as poor results of the orthostatic test after 4 months, are presented. These results are explained as applied to sedentary workers and recommendations are given for such persons to exercise in the morning, at work and in the evening in order to prevent hypokinesis and its physical, mental and physiological effects.

Kovalenko, Y. A.↗

NASA NTRS1980

The effect of hypodynamia on mineral and protein metabolism in calcified tissues of the maxillodental system (experimental radioisotope study)

Mineral and protein metabolism was studied in experiments on 60 white rats, using P-32 and Ca-45 uptake in the mineral fractions, 2C-14-glycine in the protein fractions, and P-32 in both fractions of calcified tissues as indices over a 100 day period of experimental hypodynamia. Combined alterations in mineral and protein metabolism occurred in the calcified tissues of the experimental animals. The most pronounced changes were found in P-32 and 2C-14-glycine metabolism. In the incisors and femoral bones, these alterations occurred in two phases: P-32 and 2C-14-glycine uptake first increased, then decreased. Changes in Ca-45 metabolism were less pronounced, particularly in the initial period of the experiment. A marked reduction in P-32, Ca-45, and 2C-14-glycine uptake was found in various fractions of the calcified tissues on the 100th day of experimental hypodynamia.

Prokhonchukov, A. A.↗

NASA NTRS1980

Mechanisms of water-salt metabolism disturbances in dogs subjected to six month hypokinesia

Water-salt metabolism in dogs during prolonged restricted motor activity (hypokinesia) was investigated. It was found that hydration occurred and fluid was redistributed between the extra- and intra-cellular sectors. Also, electrolyte excretion rose, and magnetism and calcium metabolism changed significantly. It is concluded that the forces caused by muscle strain proper (which was decreased under conditions of hypokinesia) influence the state of bone metabolism.

Korolkov, V. I.↗

NASA NTRS1980

Changes of the body functions during long-term hypokinesia

Prolonged hypokinesis (100-170 days) studied in 2000 rats kept in cages limiting their mobility provoked considerable changes in the gaseous and energetic metabolism: an elevation of the total gaseous metabolism and of the rate of O2 requirement by the muscles (in the late periods of hypokinesis) and a change in the intensity of tissue respiration of the liver and myocardium. There also proved to be a reduction in the level of phosphorylation and separation of oxidative phosphorylation in the myocardium, liver, and partially in the skeletal muscle. Prolonged hypokinesia led to changes in tissue metabolism: a disturbance of development of the animals, a marked delay and an increase in the weight of the organism and the muscular system, and disturbances of the mineral and protein metabolism. Prolonged hypokinesis also lead to exhaustion of the hypothalamus-hypophysis-adrenal cortex system.

Kovalenko, Y. A.↗

NASA NTRS1980

Ideas of I. M. Sechenov in aviation and space medicine

The contributions I. M. Sechenov (19th century) made to modern physiology are described, including his studies on gases in the blood (O2 and CO2), and how these studies were the basic building blocks of current efforts in aviation and space medicine. Sechenov also studied hypokinesia, which is becoming important in long duration space flights.

Gazenko, O. G.↗

NASA NTRS1979

Changes of gas metabolism, gas homeostasis and tissue respiration in rats during prolonged hypokinesia

The oxygen uptake and tissue gas homeostasis of restrained albinic rats remained relatively constant during a 60 day experiment. The gas metabolism in some tissues changed, and O2 consumption increased in the liver and decreased in the myocardium. Capacity for physical work was reduced by five times. Hypokinesia for 60 days resulted in a delay in the animals growth.

Popkov, V. L.↗

NASA NTRS1978

Pathophysiological aspects of the problem of prolonged hypokinesia

The changes in man's acitivity due to modern life with automation and sedentary activities and man's exploration of space in a state of weightlessness have accentuated the importance of hypokinesia. The pathogenesis of hypokinesia is discussed. Experiments and results made on man and animals are included.

Kovalenko, Y. A.↗

NASA NTRS1975

Pathophysiological analysis of the effect of weightlessness on the body

A general scheme of pathogenesis of the effect of weightlessness on the human body is constructed that considers a shift of body fluids, decrease and change in afferent impulses, and metabolic changes in muscle and bony tissues.

Kovalenko, Y. A.↗

NASA NTRS1974

The problem of hypoxia, hyperoxia and hypercapnia in space physiology

The dynamics of basic functional systems and behavioral reactions depend on the oxygen regime of the human body when confined in pressurized compartments during space flight. Permissible concentrations of oxygen, carbon dioxide and other gases to avoid symptoms of hypoxia, hyperoxia and hypercapnia are discussed in relation to numerous human tolerance studies.

Agadzhanyan, N. A.↗

NASA NTRS1974

The internal nature of functional disturbances arising in the body under the effect of extreme factors

Physiological factors in human tolerance and adaptation to pressurized cabin atmospheres during manned space flight are analyzed. It is shown that individuals display different degrees of functional changes and disturbances despite identical indices of compensation by the body of external factors. The significance of reactions at the cellular tissue level to factors of an altered gaseous environment is emphasized.

Gramenitskiy, P. M.↗

NASA NTRS1974

Studies of hypokinesia in animals to solve urgent problems of space biology and medicine

The effects of hypokinesia on animals were studied by observing: (1) hormonal and mediator balance of the body; (2) gas exchange and tissue respiration; (3) protein content in skeletal muscles; (4) structure of skeletal muscles; and (5) function of skeletal muscles. Sharp limitation of motor activity causes interconnected processes of a dystropic and pathological character expressed as a reduction in the force of various muscle group with disturbance of velocity properties and motor coordination due to disturbances in the control link of the neuromuscular system.

Baranski, S.↗